A high density of tumor-infiltrating lymphocytes (TILs), particularly CD8+ T lymphocytes, in rectal cancer is associated with better prognosis, suggesting that ICIs have promising antitumor effects in rectal cancer (4, 5).Radiation enhances CD8+ T cell infiltration in tumors and improves local tumor control, long-term survival, and protection against tumor rechallenge (6–8). This evidence concerns the gene CD8A and rectal cancer.